Relay contact



p 1932- K. M; LEDEREIQ RELAY CONTACT Filed April 3, 1950 Patented Sept.27, 1932 UNITED STATES PATENT KARL M. LEDERER, OF NEWARK, NEW JERSEY,ASSIGNO R TO WESTON ELECTRICAL INSTRUMENT CORPORATION, OF NEWARK,

JERSEY RELAY CONTACT Application filed April 3,

5 controlling relatively high currents.

An object of my invention is to provide a relay contact element having abufling member or members, which contact element is simple, strong,inexpensive to manufacture and easily assembled.

A further object is to produce a relay contact element of the typeincluding a resilient bufling member which is capable of carrying ahigher current than other control elements of the same general type.

Still another object of my invention is the provision of a contactelement in which a buffing member also serves to cause wiping contactbetween the contact element and the stationary contact members.

Other objects will be apparent from the accompanying drawing and thedescription thereof, in which drawing:

Fig. 1 is a plan view of the contact element.

Fig. 2 is a side view, partially in crosssection,

Fig 3 is an oblique view of the auxiliary contact member, and V Fig. ftis a fragmentary view showing the contact element in one of its closedcircuit positions, together with a stationary contact member. Thecontact element comprises, in its preferred form, two members, a maincontact member 1 in the form of a pointer cross and an auxiliary contactmember 2.

The main contact member is formed by punching a member of the propersize and shape from a sheet of aluminum or hard drawn sheet copper. Itis given the shape of a cross, of which one arm 2 constitutes thepointer or contact arm and the remaining arms 4, 5, 6, constitutebalance arms to balance the weight of the pointer arm. 7 V

The auxiliary contact member 2 is made from contact material such asplatinum, platinum-iridium alloy, silver alloy or equivalent materialand is in the form of a channel from which a portion ofthe web has beenremoved. This construction provides 1930. Serial to. 441,411,

a short, channel having parallelfingers 7,

extendingtherefrom.

Th channeled portion 90f the auxiliaryli' contact 'memberisse'cured; bymeans of a rivet 10 to an' offset portion ll of the pointer arm 3situated substantially midway'between the ends of; the pointer arm. Theweb portion of the auxiliary contact member is of, I

such size that the'flanges'engage the edges of the pointer arm at theoflset portion and the fingers extend along opposite sides of the as. e,

outerportion '12 of the pointer arm. The outer portion 12 of thepointerarm is re- I du'ced in si ze so that there is an appreciable spacebetween the edges of the pointer arm auxiliary contact member.

The parallel fingers are made greater in width than the thicknessof thepointer arm so that satisfactory contact may be made be-' tween them anda cooperating stationary contact'member13. 'In order that the pointerarmwi'll -be disposed symmetrically between f theiparallel fingers, theofiset portion 11' is of such depth as to bring the center of theagainst the outer end 12 of. pointer arm 3, cone NEW JERSEY, 1ACORPORATION or NEW You and the sides; of the parallel fingers of the I Vv 7f outerfportlon of the P01111781 arm opposite" twisting of the ptacting therewiththroughout a considerable area,becauseof:,theresiliency ofthe arm of the auxiliary-contact member. Current will thenflow through the parallel finger 7 and the pointer arm 3. r

The parallel fingers 7, 8 being constructed of resilient material, willoffer some resist ance to the movement of the contact element againstthe stationary contact member and will thus absorb most of the shockincident to element is in its plane of movement,thecontact element isrelatively rigid and reinforces the thin contact fingers after it hasflexed into engagement with the contact element.

The pointer arm is of relatively large cross-section and a good heatconductor. When it is forced up againstone of the parallel fingersand-contacts with it through a r ela-,v

tively large portion of the area, any'heat which may be developed at thepoint of contact between the parallel arm andthestatiom ary contact'member is ilbSOIbGdllflllClfiCOIl-q ducted away and no harmful heatingof the contact surfaces is possible.

It is apparent that the invention is particularly useful in theembodiment slrown above but isin no way restricted to that use but maybe used in anytype of single or multiple contact apparatus whereit'is-desired to have a contact member provided with buifing means andcapable of carrying relatively high currents. Iclaim: v- .1. In a relaycontact element for cooperation with a fixed contact element, the combi-I nation with a" relatively rigid main membeif of cruciform'sha-pehavingone arm reduced in size adjacent the endlthereof, of anauxiliary'member of flexible material securfedto the larger portion ofsaid arm and. havinga pairof parallel fingers extending along and spacedfrom the reduced, portionoflsaid arm, the end portions of saidfing'ersbeing disposed to lie against. the reduced portion ofsaid'arm whensaidelement cooperates with a fixed contact element. l, 1

2. In a relay contact element,-the combina: tion-with anelongated,thin-, sheet-metal main member having an offsetportionintermediate its ends and reduced portion-adjacent one end, .ofan auxiliary member ofhighly flexible materiallhaving the formofa chan:nel with aportion of :the web remo-vedlto provide a pairof'parallelfingers,-an d means for securing the web portion of. saidauxih iarymember to the oflsetlportion of-said main member ,witlrsaid fingersextending along and normally spaced from-thereduced portion andpositioned; .to contact with 1 the reduced portion when said contactelement abuts a; stationary contact velement, whereby said membersmutually reinforce one anv In testimony Wher\eof,.I aflixmy signature.KARL M. LEDERER. v

